A typical electric cable generally comprises a conductor that is surrounded by one or more layers depending on the application area. E.g. power cable has several layers of polymeric materials including an inner semiconducting layer, followed by an insulating layer, and then an outer semiconducting layer. To these layers, one or more further auxiliary layer(s) may be added. The outer protecting polymeric layer is known i.a. as a jacketing layer. Any of the layers can be crosslinked as well known in the field.
One of the targets in polymer, i.a. polyethylene (PE) polymer, development has been to combine i.a. high flexibility while maintaining other useful mechanical properties. For instance desired mechanical properties in wire and cable (W&C) applications, e.g. in linear low density polyethylene (LLDPE) jacketing layer applications, include i.a. abrasion resistance.
Moreover, the combination of a high heat distortion temperature (HDT) and a high flexibility is desirable for polymers, such as LLDPE, e.g. when used e.g. in cable layers, such as in jacketing layer. However, in general a higher flexibility results normally in a lower heat distortion temperature.
Multimodal PE provides one way of tailoring the polymer properties. Moreover, e.g. single site catalyst (SSC) offers a controlled incorporation of comonomers which provides a further means for tailoring the polymer. However one of the major problems of PE produced using SSC is often the processability of the polymers.
There is a continuous need in the polymer field to find polymers which are suitable for demanding polymer applications, particularly for W&C applications, where the cable materials must meet high requirements and stringent authority regulations.